tools: disable building qemu-trad per default

Using qemu-traditional as device model is deprecated for some time now.

So change the default for building it to "disable". This will affect
ioemu-stubdom, too, as there is a direct dependency between the two.

Today it is possible to use a PVH/HVM Linux-based stubdom as device
model. Additionally using ioemu-stubdom isn't really helping for
security, as it requires to run a very old and potentially buggy qemu
version in a PV domain. This is adding probably more security problems
than it is removing by using a stubdom.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: Ian Jackson <iwj@xenproject.org>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>

CHANGELOG.md

@@ -18,6 +18,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
    or by passing "iommu=quarantine=scratch-page" on the hypervisor command line.
  - pv-grub stubdoms will no longer be built per default. In order to be able to use pv-grub
    configure needs to be called with "--enable-pv-grub" as parameter.
+ - qemu-traditional based device models (both, qemu-traditional and ioemu-stubdom) will
+   no longer be built per default. In order to be able to use those, configure needs to
+   be called with "--enable-qemu-traditional" as parameter.
 
 ## [4.15.0 UNRELEASED](https://xenbits.xen.org/gitweb/?p=xen.git;a=shortlog;h=RELEASE-4.15.0) - TBD
 

stubdom/configure

@@ -2286,14 +2286,6 @@ fi
 # Check whether --enable-qemu-traditional was given.
 if test "${enable_qemu_traditional+set}" = set; then :
   enableval=$enable_qemu_traditional;
-else
-
-    case "$host_cpu" in
-        i[3456]86|x86_64)
-           enable_qemu_traditional="yes";;
-        *) enable_qemu_traditional="no";;
-    esac
-
 fi
 
 if test "x$enable_qemu_traditional" = "xyes"; then :

stubdom/configure.ac

@@ -27,13 +27,7 @@ AX_STUBDOM_DEFAULT_ENABLE([xenstorepvh-stubdom], [xenstorepvh])
 AX_STUBDOM_CONDITIONAL([vtpm-stubdom], [vtpm])
 AX_STUBDOM_CONDITIONAL([vtpmmgr-stubdom], [vtpmmgr])
 
-AC_ARG_ENABLE([qemu-traditional],,,[
-    case "$host_cpu" in
-        i[[3456]]86|x86_64)
-           enable_qemu_traditional="yes";;
-        *) enable_qemu_traditional="no";;
-    esac
-])
+AC_ARG_ENABLE([qemu-traditional])
 AS_IF([test "x$enable_qemu_traditional" = "xyes"], [
     qemu_traditional=y],[
     qemu_traditional=n

tools/configure

@@ -1502,8 +1502,8 @@ Optional Features:
   --disable-seabios       Disable SeaBIOS (default is ENABLED)
   --disable-golang        Disable Go tools (default is ENABLED)
   --enable-qemu-traditional
-                          Enable qemu traditional device model, (DEFAULT is on
-                          for Linux or NetBSD x86, otherwise off)
+                          Enable qemu traditional device model, (DEFAULT is
+                          off)
   --enable-rombios        Enable ROMBIOS, (DEFAULT is on if qemu-traditional
                           is enabled, otherwise off)
   --disable-ipxe          Enable in-tree IPXE, (DEFAULT is on if rombios is
@@ -4287,19 +4287,6 @@ LINUX_BACKEND_MODULES="`eval echo $LINUX_BACKEND_MODULES`"
 # Check whether --enable-qemu-traditional was given.
 if test "${enable_qemu_traditional+set}" = set; then :
   enableval=$enable_qemu_traditional;
-else
-
-    case "$host_cpu" in
-        i[3456]86|x86_64)
-           enable_qemu_traditional="yes";;
-        *) enable_qemu_traditional="no";;
-    esac
-    case "$host_os" in
-        freebsd*)
-           enable_qemu_traditional="no";;
-    esac
-
-
 fi
 
 if test "x$enable_qemu_traditional" = "xyes"; then :

tools/configure.ac

@@ -120,18 +120,7 @@ AC_SUBST(LINUX_BACKEND_MODULES)
 
 AC_ARG_ENABLE([qemu-traditional],
     AS_HELP_STRING([--enable-qemu-traditional],
-                   [Enable qemu traditional device model, (DEFAULT is on for Linux or NetBSD x86, otherwise off)]),,[
-    case "$host_cpu" in
-        i[[3456]]86|x86_64)
-           enable_qemu_traditional="yes";;
-        *) enable_qemu_traditional="no";;
-    esac
-    case "$host_os" in
-        freebsd*)
-           enable_qemu_traditional="no";;
-    esac
-
-])
+                   [Enable qemu traditional device model, (DEFAULT is off)]))
 AS_IF([test "x$enable_qemu_traditional" = "xyes"], [
 AC_DEFINE([HAVE_QEMU_TRADITIONAL], [1], [Qemu traditional enabled])
     qemu_traditional=y],[